Type-writing machine.



F. A. COOK.

TYPE WRITING MACHINE.

APPLlCATlON FlL'ED JUNE 17. 1914.

Patented Apr. 17, 1917.

WWN ESSES 7 L W W main eras 1o ATENT Wm GEO FRANK AUCOOK, 0F HARTFORD,CONNECTICUT, ASSIGNOR T0 UNDERWOOD TYPE- WRITER COMPANY, OF NEW YORK, N.Y., A CORPORATION OF DELAWARE.

TYPE-WRITING MACHINE.

Specification of Iletters Patent.

Application filed J une 17, 1914. Serial No. 845,518.

To all whom it may concern:

Be it known that I, FRANK A. COOK, a citizen of the United States,residing in Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in Type-Wr'iting Machines, of which the following is a specification.

This invention relates to the case-shift mechanism of typewritingmachines, and particularly to keys which look and unlock the case-shiftmechanism.

In the Underwood typewriting machine, to which my improvements areillustrated as applied, a shift-key is provided at the lefthand side ofthe key-board, for the vusual purpose of shifting the mechanismtocapital printing position; and at the right-hand side of the key-board,it is customary to provide asimilar shift key, which upon beingdepressed, will not only shift the mechanism to capital printingposition, but Will alsolock it in such position; and a release of saidlock could be effected by depressing said shift key at the left-handside of the keyboard.

It is found desirable in practice, that there should be not only a keyat the left, but also one at the right of the key-board for efi"ecting atemporary shift of the mechanlsl'n to capital printing position, so thatthe operator may depress by either his left hand or his right hand, acapital shift key, and so that upon releasing either of said keys, themechanism will shift back to its normal position.

An object of my invention is to provide a simple and inexpensive meansreadily applicable to existing machines in manufacture vfor eflectingthis result of having either the left-hand or the right-hand key usablefor a temporary shifting of the shift mechanism, while l-also make aprovision for permanently shifting said mechanism,

that is for locking the case-shift mechanism in its shifted position. Inthe case of the Underwood machine, the shift keys lift the platen sothat the capital types will strike thereon.

According to my present improvements, the left-hand shift key serves fortemporarily shifting and also for releasing the platen when it has beenlocked up. The righthand shiftkey mounted on a platen-shifting leverwhich is used for temporary shifting. Upon the right-hand key lever is apin or projection, and pivotally mounted upon the frame of the machineis a springpressed latch, the office of which is to catch over said pinor projection to lock down said right-hand shift key when the latter isdepressed but I mount upon the right-hand key lever a foil or trip whichdisables said latch, so that it is prevented from catching over saidpin. A spring retains this trip in normal position, so that Wheneversaid right-hand shift key is depressed, the latch is unable to catchover the pin.

To make it possible to lock down the right-hand shift key, Iprovide aseparate key which is mounted upon said trip to press the same down toinefi'ective position so that it cannot restrain said latch or lock fromcatching over the pin on said shift key lever. This trip, which may bein the form of a lever, is capable of limited movement upon the mainshift key lever; serving in its elevated position to render said latchinefiective, and also serving when pressed down by the finger of theoperator, to release said latch to enable it to catch over the pin. Akey on this trip also serves to shift the platen. From this, it resultsthat the left-hand key lever may be used for temporary shifting of theplaten, and that the right-hand key lever may be employed for the samepurpose, and that the trip key may be depressed for shifting the platenand locking the same in its shifted position.

The latch may be released by the means usual in the Underwoodtypewriting inachine, a pin upon the left-hand key lever engaging a cam,and the latter fixed on a the operator Patented Apr. av, teat.

release the same by the usual cally.

Other features and advantages will hereinafter appear.

Inthe accompanying drawing,

Figure 1 is a front perspective elevation showing a portion of atypewriter carriage, the platen frame, and mechanism with operating keysfor shifting the platen verti- Fig. 2 is a side elevation of the sameshowing the platen as shifted to the upper-caseposition, and theshifting mechanism locked.

Fig. 3 is a perspective detail View of the foil device and trip for thelatch or look, with lever and key to shift and lock the platen inshifted position.

Fig. 4 is a detail partial side elevation showing the right-hand keylever for the temporary and permanent shifting of the platen with thefoil and lock-trip device mounted thereon, the foil being here shown aspreventing the operation of the latch or lock, the left-hand temporaryshift lever also being shown.

Fig. 5 is a similar view illustrating the lock releasing means operatingin conjunction with the depression of the left-hand shift lever.

The operating parts of an Underwood typewriting machine to. co-act withthis invention, and here shown to afford a full comprehension thereof,include the carriage 1, a portion only whereof is illustrated, theplaten frame 2, the platen 3 mounted therein, the swinging rail 4supported by brack-- ets 5 mounted on rock shaft 6, which is journaledin the machine frame 7 the rail 4 supporting the platen frame by meansof roller 8 thereon, and said rail 4 being shiftable through thecontacting swinging action of the extensions 9, 10, respectively, of theshift levers 11 and 12; the platen frame being guided in its shiftingmovements by the rock shaft 13 having frame-engaging arms 14.

.The key levers 11 and 12, fulcrumed on a shaft 15 and held normallyelevated as by spring 16, are provided respectively with finger-keys 17and 18 arranged respectively at the right and left hand sides of themachine, in the usual arrangement relative to the keyboard.

Said finger-keys 17 and 18 are temporary shift keys by means of whichthe operator may shift the platen to the upper-case position, as forwriting capitals and other upper-case characters, with either the leftor right hand holding the finger-key depressed for temporary use of theplaten in that shifted position, and releasing the key to allow theplaten to resume its normal or lower-case position, the advantage ofthis feature of the invention being that the occasion for a temporaryshift may occur when either one of the operators hands can moreconveniently be used for actuating the shift lever than the other. 1t isa purpose of my invention to provide the convenience aforesaid inaddition to theprovision of meansat one side of the machine whereby theshift' mechanism may be locked when the platen has been shifted to theupper-case positron. The feature of my invention wherein I provide thedual capacity at one side of the machine of shifting the platen eithertemporarily or permanently at will involves a and a lug 22 on said lever2O engaging with the lever 11 to hold said-levers normally inparallelism.

The lever 11 has a lateral projection or pin 23, a lockinglatch 24mounted on a rock shaft 25 that is journaled in the machine frame beingadapted to engage said projection 23 when the lever 11 is depressed andit is desired to lock the shift mechanism. Said latch 24 has'a rear camsurface 26, which engages the projection 23 at the depression of thelever 11, whereby said latch and the rock shaft 25 are rocked forwardlyduring descent of said projection past said cam surface beforeengagement of the projection with the catch, the rock shaft 25 beingunder spring tension in this rocking action and throwing the latch overthe projection to effect the lock when the projection 23 has passed thecam surface 26.

But when the finger-key 17 is to bedepressed for the temporary shiftingoperation, it is not desired that the latch 24 shall engage with theprojection 23, and the latch 24 is therefore provided with a forward camsurface 27 below the pivot 25 thereof, and the lever 20 carries a foilor lug 28 to cooperate with said cam surface 27 during the depressingmovement of lever 11 to move and hold the latch 24 and to therebyprevent the rock shaft 25 from swinging the catch 24 into engagementwith the projection 23 when, said lever is fully depressed.

At the point of maximum depression of the lever 11 through the actuationof fingerkey 17, the latch 24 will present its cam surface 27 to thefoil or lug 28 in the position ver 11 for shifting the platen andlooking it in the shifted position, a second finger-key neeavee 29,"forming a permanent shift key for said .lever, is depressed, saidfinger-key 29 being wardly with the further depression of lever 20 toshift the platen upwardly in the same manner as thoughthe key 17 hadbeen operated. While the degree of depression of the key lever 11 whenoperated by finger-key 17 carries the foil 28 to its operative positionshown in Fig. 1 to prevent engagement of the lock, the lever 20 iscapable ofdepression to a greater extent. in which to carry the foil 28below thecam surface 27, to thereby release the latch 24: and allow thespringactuated rock shaft 25 to swing the latch 24 into engagement withthe projection 23, thus locking the lever 11 in the shifted position.The hook 30 on lever 20 becoming seated upon projection 23 while saidlever 20' is being depressed, thus communicates the movement of lever 20to lever 11, and thereby permits the key 29 to operate the shift leverand enables it to become locked in the shifted position. I

The foil or lug 28, when passed beyond the cam 27 to trip the catch,engages beneath the catch throughsthe tension of the return springs forlevers 11 and 20, thereby forming practically a double lock, because thelatch 24 is thus held both by its upper or.

hook portion and tion.

In order to release thelocking engagement aforesaid, the latch 24 isswung rearwardly by independent means. lhe rock the back of its lowerporshaft 25 carrying said latch 2% also carries a cam 31 lying in thepath of a projection or pin 32 upon a key lever such as that shown at12. The rock shaft 25, as before stated I with regard to the latch 24:,is urged to rock in that direction which enables it to move the catchrearwardly, and consequently to also urge the cam 31 rearwardly. lihetensional means here shown for so controlling the rock shaft 25comprises a spring 33 bearing upon a lever 34 which engages a cam uponthe rock shaft at an angle to the cam 31, but obviously other springcontrolling means may be employed.

The lever'12, as before stated, may be depressed for the temporaryshifting of the platen, and in addition to that function it serves as arelease for the lock shift. The mode of operation when releasing thelock is illustrated in Fig. 5, wherein the lever 12 is represented aspartly depressed, with the projection 32 displacing the cam 31, therebyplaten,

rocking the shaft 25 so that the cam 27 rides 4 rearwardly over the foil28 and is in fact at Fig. 5 shown in the act of leaving said foil, thelatch at the sametime leaving the projection 23 (not shown in Fig. 5),and thereby allowing the lever 11 to return to normal position. v

The separate shift levers 11 and 12, with their finger-keys, may, as.usual, be provided at the opposite sides of the bank of keys, as 36, forconvenience in enabling the operator to manipulate them respectivelywith the right .and left hands, and the desirability-of using either oneof said key levers fortemporary shifting purposes is apparent,particularly as the mere addition of a further key upon one of theselevers enables it to be also employed as a shift look.

When the key for the shift lock is provided upon the right-hand lever,the practice is identical with that in vogue, and also when theleft-hand lever is used as the lock release, the operator has no newarrangement to learn, but is supplied with the advantage of being ableto use either hand for the temporary shifting of the laten.

. The temporary key 1 has a shorter range of movement than the permanentkey 29, which is an advantage because the temporary shift is much morefrequently used than the permanent or locking shift, and it is desirablein temporarily. shifting the to eliminate alllost motion in the shiftkey, so that the entire stroke of the key is utilized in shifting theplaten, and said stroke may be as short as is consistent with an easyshifting of the platen. The permanent key- 29 has a movement about the,

scope of the invention, and portions of the improvements may be usedwithout others.

Having thus described my invention, 1 claim:

1. The combination of a shift key lever, a permanent key to operate saidlever, a lock effective at the operation of the lever by said permanentkey to hold the lever permanently in operated position,'a temporary keyto operate said lever, and a releasable trip carried by said permanentkey normally effective at the operation of the lever by said temporarykey to move and hold the lock in ineffective position, said tripmovable. by said permanent key from an operative to an inoperativeposition.

2. The combination of a shift key lever, a lock to hold the lever inoperated position, a releasable trip normally effective at the operationof the lever to move and hold the lock in ineffective position, and alever-opcrating key connected to said trip for mov- 13o ing the triprelatively to the lever to a position in which it is ineffective toprevent op eration of the lock, said lock effective at the operation ofthe lever by said key to lock the lever in its operated position.

3. The combination with a shift lever and a key to actuate the same, ofa lock, a device operative when the lever is actuated by said key, todisable said lock, and an auxiliary key for operating said lever, saidauxiliary key having a limited movement relatively to the lever, saiddisabling device being operable by said auxiliary key to a position torelease the lock, said lock operable auto- -matically at the operationof the lever by said auxiliary key, to lock the lever in operatedposition.

4. The combination with a shift lever and a key to actuate the same, ofa look, a device operative when the lever is actuated by said key, todisable said lock, an auxiliary key for operating said lever, saidauxiliary key having a limited movement relatively to the lever, saiddisabling device being operable by said auxiliary key to a position torelease the lock, said lock operable automatically at the operation ofthe lever by said auxiliary key, to lock the lever in operated position,a second shift lever operable independently of the first-mentionedlever, and means operated by said second lever to unlock the firstlever.

5. In a typewriting machine, the combi-.

nation of a key-actuated case-shift lever, a look, a spring to throw-thelook into locking engagement with the lever, a trip carried by the leverand normally operative to hold the lock out of use when the lever isoperated, and an auxiliary key to operate said lever and to move thetrip relatively to the lever to release the lock, whereby the lever isautomatically locked when actuated by the auxiliary key.

6. In a typewriting machine, the combination of a key-actuatedcase-shift lever, a lock, a spring to throw the lock into lockingengagement with the lever, a trip carried by the lever and normallyoperative to hold the lock out of use when the lever is operated, anauxiliary key to operate saidlever and to move the trip relatively tothe lever to release the lock, whereby the lever is automatically lockedwhen actuated by the auxiliary key, a second case-shift lever, a rockshaft to which said lock is connected, and acam on said rock shaftactuated by said second lever to swing the lock to ineffective position,whereby said second lever may be operated to release the first-mentionedlever.

7. in a typewriting machine the combina- .tion with a sliiftable platen,of a temporary shift lever for shifting said platen, a permanent shiftkey carried by said lever, a lock normally in efiective position to lockthe platen in shifted position, a trip carried by said permanent key forengaging and shifting said lock to ineffective position on depression ofsaid temporary key, said permanent key engaging and shifting said lock,but passing to a position free therefrom on operation of said permanentkey.

8. In a typewriting machine, the combination with a shiftable platen, ofa shift lever having a finger key, a lock for said lever, alock-controlling device movably mounted 011 said lever to control thelock and operable when the lever is depressed by said key to render thelock ineffective, said controlling device having a finger key whoseoperation serves to both shift the platen and move said controllingdevice on said lever into position to permit the lock to lock the leverin its depressed position, and releasing means for said lock independentof, said' keys.

9. In a typewriting machine, the combination with a shiftable platen, ofa shift lever, a lock therefor normally in effective position, a lockdisabling device movably mounted upon said lever and operable while inits normal position on the lever to engage and move to thereby disablesaid lock when the lever is operated, thereby causing the lever to onlytemporarily shift the platen, and a key to operate the lever and movesaid disabling device to inefiective position. on the lever, whereby theplaten is shifted and locked. v

10. In a typewriting machine the combination with a shiftable platen, ofa shift lever therefor, a lock for said lever, a disabling device uponsaid lever operable while in it's normal position on the lever todisable said lock causing the lever to only temporarily shift theplaten, a key operableito shift said lever and concomitantly disable thelock disabling device and thereby render said lock efleetive, a secondshift lever for said platen and means operable by said second shiftlever for also disabling said lock.

11. In a typewriting machine the combination with a shiftable platen, ashift lever,

a. pivotal latch normally effective to engage said lever when depressed,a foil having a normal position on said lever in which it is operable toengage and move to thereby disable said latch when the lever isdepressed and a key on said foil for depressing the lever and shiftingthe foil to inoperative position whereby the latch'is rendered operativeto lock the lever in shifted position.

12. In a .typewriting machine,the combination with a shiftable platen,of a shifting lever therefor, means to lock the platen in its shiftedposition, a device to prevent operation of the lock, two keys on said.lever for individually operating the lever, one of said keys serving totemporarily shift the plates,

masses the other key having a limited movement relatively to the lever,and serving to both shift the platen and move said lock-preventingdevice to inoperative position to thereby permit operation. of the look,so that the platen is locked in its shifted position, and another leveroperable to release the lock.

13. In a typewriting machine, the combination with a shiftable platen,of a shifting lever therefor, two finger keys for individually operatingsaid lever, a look, a device to prevent operation of the lock, one ofsaid keys serving to temporarily shift the platen and hold said lockinoperative, so that the platen will not be locked, the other key havinga limited movement relatively to said lever, and serving by its combinedmovement with and relatively to the lever to both shift the platen andrelease said lock-preventing device, permitting the lock to lock theplaten in shifted position, and another lever operable to temporarilyshift the platen, and also operable when the platen is lockediii-shifted position, to release it.

14:. In a typewriting machine, the combination with a shiftable platen,of shifting levers therefor arranged respectively at the right and leftsides of the machine, a key on each lever, the depression of either oneof said keys serving to temporarily shift the platen, a lock to hold theplaten in its shifted position, a lock-preventing device operable toprevent operation of the look when either of said keys isdepressed, apermanent shift key pivoted on one of said levers, the depressionwhereof both shifts the platen and swings the permanent key about itspivot, and thereby moves the lock-preventing device to inoperativeposition to permit the lock to hold the platen in shifted position, andmeans operable by the key on the other lever to release'the lock.

15. In a typewriting machine, the combination with a shiftable platen,of shifting levers therefor arranged respectively at the right and leftsides of the machine, a tern: porary shift key for each lever, thedepression of either one of said keys serving to term porarily shift theplaten, a permanent shift key shiftably mounted on said right-handlever, a lock for said right-hand lever rel dered inoperative by theoperation of a temporary shift key, and sleek preventing de viceoperable when said permanent key 1S depressed, whereby the operation ofsaid permanent key both sh "ts the platen and locks it in shiftedposition, the depression of the left-hand lrey serving to release thelock. c n

16. ln a typewriting machine, the com nation with a shiitableplaten, ofrig hand shift lever and a left-hand shift lever, said levers separatelyoperating to tempo rarily shift the platen, a projection on saiddepressed, to depress right-hand lever, a pivotal spring-pressed latchadapted to engage said projection for locking said lever when depressed,a foil mounted to swing on said lever and normally positioned on thelever to prevent said latch from engaging said projection when the leveris depressed, whereby said lever normally operates as a temporary shiftlever, and a key to depress said lever'and swing the foil into positionto release the latch and permit it to lock the lever in depressedposition.

17. ln a typewriting machine, the combination with a shiftable platen,ofa righthand shift lever and a left-hand shift "lever, said leversseparately operating to temporarily shift the platen, a projection onsaid 'rlght-hand lever, a pivotal spring-pressed latch adapted to engagesaid projection for locking said lever when depressed, a foil carried bysaid lever to normally prevent said latch from engaging said projection,where by said lever normally operates as a temporary shift lever, andmeans for movin said foil to release said latch in the depresslon ofsaid lever to thereby permit said latch to engage said projection andlock the lever in shifted position. p

18. In a typewriting machine, the combination with a shiftableplaten, ofa righthand shift lever and a left-hand shift lever, said leversseparately operating to temporarily shift the platen, a projection onsaid right-hand lever, a pivotal spring-pressed latch adapted to engagesaid projection for locking said lever whendepressed, a foil carried bysaid lever. to normally prevent said latch from engaging saidprojection, whereby said lever normally operates as a temporary shiftlever, and means for movingsaid foil to release said latch in thedepression of said lever to thereby permit said "latch to engage saidprojection and lock the lever in shifted position, the depression ofsaid left-hand lever serving to release said latch and allow theright-hand lever to re turn to normal position,

it). in a typewriting machine, tl combination with a shiftable platen, oa righthand shift lever and left-hand Sl'llle lever, said leversseparately operating temporarily shift platen, a projection i saidright-hand lever, a pivotal spring ,ressed latch to engage saidprojection for locking said lever when depressed, r: held foil or tripcarried by said normally prevent said latch from projection, wher 1y salever operates as tempor. 1r

carried by said foil lever amrender said foil ineilective, wherebyengagement of the latch with said pro ection 15 effected and the le erheld shifted position,

projection, whereby said lever normallyoperates as a temporary shiftlever, and means for moving said foil to release saidlatch in thedepression of said lever to thereby permit said latch to engage said proection and lock the lever in shifted position.

21. In a typewriting machine, the combination with a shift'able''platen, of a righthand shift lever and a left-hand shift lever, saidlevers separately operating to temporarily shift the platen, a projectonon said right-hand lever, a pivotal spring-pressed latch adapted toengage said projection for locking said lever when depressed, aspringheld foil or trip carried by said lever to normally prevent saidlatch from engaging said projection, whereby sa d lever normallyoperates as a temporary shiftv lever, and means for moving said foil torelease said latch in the depression of said lever to'thereby permitsaid latch to engage said pro ection and lock the lever in shiftedposition, the depression of said left-hand lever serving to release saidlatch and allow the right-hand lever to return to normal position.

22. In a typewriting machine, the combination with a sliiftable platen,of right and left-hand shift levers each having a finger key, each ofsaid levers being separately operable to temporarilyshift the platen, aprojection on one ofsaid levers, a springpressed pivotal latch having acam surface to engage said pro ection and move said latch into positionto lock over said pro ection upon the depression of said lever, aspring-held foil or trip mounted on said lever normally engaging saidlatch to prevent it from engaging with said pro ection whereby saidlever operates as a temporary shift lever, and a finger key for saidfoilor trip, the depression whereof releases said foil from said latchlocking engagement with said lever as the latter is depressed.

23. In a typewriting machine, the com-\ bination with a shiftableplaten, of right and left-hand shift levers each having a finger key,each of said levers being separately operableto temporarily shift theplaten, a projection on one of said levers, a spring-pressed pivotallatch having a cam surface to engage said projection and move said latchinto position to lock over said projection uponthe depression of saidlever, a spring-held foil or trip mounted on and trips the latter into rsaid lever normally engaging said latch to prevent it, from engagingwith said projection whereby said lever operates as a temporary shiftlever, a finger key for said foil or trip, the depression whereofreleases said foilfrom said latch and trips the latter into lockingengagement with said lever as the latter is depressed, and meansoperated by the other lever to release said lockingengagement.

shiftable platen, the combination with a right-hand shift lever and aleft-hand shift lever each having a finger key, each of said leversbeing separately operable to temporarily shift the platen, a rock shaft,a latch carried bysaid rock shaft, a spring to rock said shaft andurge-said latch rearwardly, a

projection on one of said levers, said latch having a cam surface inthe'path of said projection, whereby said latch is swung forwardly uponthe depression of said lever to be thereby in position to engage withsaid projection, an auxiliary lever pivoted on said shift lever, asupporting spring therefor, a foil carried by said auxiliary lever toengage said latch'and normally restrain said atch from engaging withsaid projection, and a finger key for said auxiliary lever to depressthe latter and the shift lever, the

depression of said auxiliary lever causing said shaft and urge saidlatch rearwardly,

a projection on one of said levers, said latch having a cam" surface inthe path of said projection,-whereby said latch is swung for- .wardlyupon the depression of said lever to be thereby in position to engagewith said projection, an auxiliarv lever pivoted on said shift lever, asupporting spring therefor, a foil carried by said auxiliary lever toengage said latch and normally restrain said latch from engaging withsaid projection, a finger key for said auxiliary lever to depress thelatter and the shift lever,'the depression of said auxiliary levercausing the foil to trip the latch and allow it to enter into look ingengagement with said projection, and a cam near the opposite end of saidrock shaft,

the other shift lever having a projection to engage said cam, therebyrocking said shaft to release the locking engagement of said latch assaid other lever is depressed.

26. In a typewriting machine having a shiftable platen, the combinationof a righthand shift lever and a left-hand shift lever 24. In atypewriting machine having a engagement with said proeach having afinger key, each of said levers being separately operable to temporarllyshift the platen, a rock shaft, a latch carried by said rock shaft, aspring to rock said shaft and urge said latch rearwardly, a projectionon said right-hand lever, said latch having a cam surface in the path ofsaid projectlon, whereby said latch is swung forwardly upon thedepression of said righthand lever to be thereby in position to engagewith said projection, an auxiliary lever pivoted to said right-handshift lever, a supporting spring therefor, a foil carried by saidauxiliary lever to engage said latch and normally restrain said latchfrom engaging with said projection, and a finger key for said auxiliarylever to depress the latter and the right-hand shift lever, thedepression of said,auxiliary lever causing the foil to trip the latchand allow it to enter into locking engagement with said projection.

27. In a typewriting machine having a shiftable platen, the combinationof a righthand shift lever and a left-hand shift lever each having afinger key, each of said levers being separately operable to temporarilyshift the platen, a rock shaft, a latch carried by said rock shaft, aspring'to rock said shaft and urge said latch rearwardly, .a projectionon said right-hand lever, said latch having a cam surface in the path ofsaid projection, whereby said latch is swung forwardly upon thedepression of said righthand lever to be thereby in position to engagewith said projection, an auxiliary lever pivoted to said right-handshift lever, a supporting spring therefor, a foil carried by saidauxiliary lever to engage said latch and normally restrain said latchfrom engaging with said projection, a finger key for said auxiliarylever to depress the latter and the right-hand shift lever, thedepression of said auxiliary lever causing the foil to trip the latchand allow it to enter into locking engagement with said projection, anda cam near the opposite ,end of said rook shaft, the left-hand shiftlever having a projection to engage said cam, thereby rocking said shaftto release the locking engagement of said latch as said left-hand leveris depressed.

28. In a typewriting machine, a case shifting mechanism including ashiftable member, in combination with two levers, each having a key atits forward end and fulcrumed at its rear end and connected to saidshiftable member in a manner such that each key may temporarily shiftsaid member without movement of the other key, the connection betweeneach key and said shiftable' member being positive, so that the firstportion of the depression of either key initiates the movement of saidshifting member, a permanent shift key lever mounted upon one of saidtemporary key levers, a locking device to cooperate with said permanentshift key, said permanent key having certain movement for controllingthe lock and additional movement for shifting said shiftable member, andmeans to enable the other temporary shift key to release the lock.

FRANK A. COOK.

Witnesses:

W. M. DYO KMAN, LYMAN l). BROUGHTON.

